One donation of blood can save up to three lives. As the need for blood continues to grow around the world, WHO and partners recognize all those who volunteer to give blood, and invite more people to be heroes by donating blood voluntarily and regularly. On World Blood Donor Day, 14 June, help spread the message, "Every blood donor is a hero," and join the conversation on Twitter @WHO - #GiveBlood. (http://twitter.com/#!/who)